Denture stress reliever



Dec. 28, 1948. w BUSBY DENTURE STRESS RELIEVER Filed May 31, 1946 J INVENTOR,

107%5? M 5&5511

Patented Dec. 28, 1948 UNITED STATES PATENT, OFFICE 2,457,529 DENTURE STRESS RELIEVER Luther W. Busby, Manhattan Beach, Calif.

Application May 31,

Claims.

My invention relates to partial dentures and more particularly to a stress reliever for reducing stresses between a partial denture and the natural teeth.

Partial dentures, those replacing less than the natural number of teeth of the upper or lower jaw, are retained in position in the mouth by means of clasps which engage the natural or abutment teeth adjacent the denture. Such dentures usually comprise a cast metal frame formed to lit the jaw and provide a base for the artificial teeth. Saddles of plastic material or metal are carried by the frame and the artificial teeth are set in the saddle. The clasps are commonly cast integrally with the metal frame and are therefore rigid in relation to the frame. When in place in the mouth, the saddles rest on the yieldable tissue of the jaw while the clasps engage the rigid, non-yielding natural teeth as aforementioned.

During mastification; the pres-sure on the denture compresses the natural tissue under the denture resulting in movement of the denture in relation to the abutment teeth. This condition imposes severe stresses upon the abutment Teeth causing discomfort to the patient and danger of loosening and possible loss of the abutment teeth.

Several attempts have been made in the past to provide attachments for use in connection with partial dentures for relieving the stresses between a partial denture and the natural abutment teeth to which the partial denture is attached. None of the prior attachments developed heretofore has, within my knowledge, come into general use. An analysis of these attachment-s has revealed disadvantages and weaknesses which the present invention is believed to have overcome.

In providing an attachment for relieving stresses between a denture and the clasps thereof, it is of primary importance that the claspson the abutment teeth provide adequate support for the denture. If the stress relievin attachment is constructed to permit universal movement between the denture and clasps, the denture may fail to function properly because of not receiving adequate support from the clasps. This is particularly true of dentures which replace posterior teeth and have anterior clasps supporting the denture only at the front, such as the denture shown in the accompanying drawings. In developing the stress relieving attachment of this invention, no attempt has been made to relieve all of the stresses which occur between a denture and clasp; to do so would deprive the denture of adequate support by the clasp.

Another weakness to be avoided in designing a 1946, Serial No. 673,674

stress relieving attachment is that of insufficient bearing surface between the relatively movable parts of the attachment. Such attachments must function many times each day under the severe stresses occurring during each cycle of movement of the jaw during mastication. Some of the stress relieving devices developed in the art have only line or point contact between the movable parts of the device. Such inadequate bearing surfaces wear rapidly and become too loose to properly support the denture.

Another essential requirement in the construction of a stress relieving attachment is that the attachment have as few parts as possible so as to achieve the highest possible degree of simplicity. A simple device having a minimum number of parts is much less costly and is less apt to become fouled by food particles.

With the above problems in mind, it is an object of my invention to provide a stress relieving attachment which will relieve major stresses and yet provide adequate support at all times for the denture.

Another object of this invention is the provision of such an attachment in which the movable parts thereof have ample bearing surfaces capable of resisting undue wear over long periods of continued use.

Still another object of my invention is the provision of a stress relieving attachment which can be readily adjusted to compensate for wear of the moving parts.

A further object provide such an attachment which may be easily taken apart for cleaning and reassembled by the patient.

A still further object of my invention is to provide a stress-relieving attachment which will allow ample movement of the denture relative to the gums and yet will prevent accidental displace-v ment or removal of the denture during mastication of sticky material.

Other objects and advantages will become apparent in the following description taken in view of the accompanying drawings, in which:

Fig. 1 is an enlarged, perspective view of the attachment as it appears before being mounted on a denture.

Fig. 2 is a plan view of a denture including two of the stress relievin attachments of the present invention.

Fig. 3 is an enlarged sectional view taken on the line 3-3 of Fig. 2.

Fig. 4 is an enlarged, vertical sectional view taken on line 4-4 of Fig. 3.

of the present invention is to sate for the yielding of Referring specifically to the drawings, a preferred form of stress relieving attachment of the present invention is generally indicated throughout the several views by the numeral ID. The attachment I0, shown in Fig. 1 as it appears before being mounted on a denture, includes a male element II having a stud I2 bifurcated as indicated at l3. Extending radially from the stud I2 is a mounting shank M for attaching the element I.I to a denture as later described. The element, I I is: formed of a single piece of Wire preferably of noncircular cross illustrated.

Slidable on the stud I2 is a sleeve t6 having the same non-circular shape of the stud 1.2.. The sleeve fits snugly on the stud I 2 which, after being bifurcated, expands to become slightly largerthan the bore of the sleeve Ill. The stud t2 yields sufficiently to be inserted into the sleeve and maintain a continuous pressure outwardly against the bore of the sleeve when in use; The, sleeve It is cut diagonally, as indicated at I1, to provide a detent l8 the purpose of which will be described hereinafter. In practice, the attachment H) is supplied with the sleeve It and stud in of excessive. length. The lengths are trimmed as requiredwhen the attachment is mounted on a given denture but are left as long as possible inorder to provide maximum stability and Wear.

Fig. 2- shows a denture 20 including a pair of the attachments Ill of the present invention. The denture 23 comprises a frame 2! having a palatal bar 22' and saddle frames 23. Molded on the saddle frames, 23 are saddles 24 of plastic. material in which artificial teeth 25 are mounted. Also included in the denture 20 are clasps 28. shaped to embrace natural abutment teeth 29. shown dotted in Fig. 2'.

The male elements it are fixed to the denture frame 2| by soldering or otherwise attaching the shanks M to the denture frame 2E. The sleeves it are attached to the clasps. 28 by so dering or by inserting the sleeves It in the mold at the time the clasps are cast, thereby permanently uniting the clasps 28. with the sleeves I. 6...

After the sleeves I6 and studs I2 are mounted on the. denture and cut. to the proper length, a notch is. filed on one side of each of the studs H. as indicated at 32 in, Fig. 4. The clasps 2.8 arethen placed in position with the studs I2 extend: ing into. the sleeves l6 and the: detents I8 of the sleeves t6, are pressedinward, into the notches 3-2 as. shown in Fig. 4. Whenthe' clasp 2-8 is. re.- moved from the stud I2, the detent I 8 engages the upper end of the notch 3t sufiiciently to yieldably resist removal of the clasp. 28.

It: will. be seen in Fig. 3. that when the denture is in position in the mouth that removal of the denture 2% from the mouth is impossible without: removal of the clasps 28 from the abutment teeth.

Should the sleeve #6 and stud I2 01' the attachment I0 become worn after continued use, the stud I2 can be enlarged by inserting, a small screw driver in the bifurcation I3 and springing the stud to increase its diameter until the proper fit between the stud and sleeve is restored.

The large areas, of the contacting surfaces of. the studs I2 and sleeves I6 transmit ample stability from the clasps 28. to the. denture frame.- 1' While permitting sufficient vertical movement. 015 the; saddles 24 relative to the. clasps 28 to c0mpen the tissues supporting the. saddles during mastication.

of the attachments I0 section such as the oval shape 5 tween said I being secured to said clasp,

, sleeve permitting relative vertical movement beand. retain said saddle in- Although I have shown and described but one preferred form of the stress relieving attachment of my invention, it is understood that various modifications and changes may be made therein Without departing from the spirit of the invention or the scope of the appended'claims.

I claim as my invention:

1. In an artificial denture, the combination of: a claspfor engagement. with. an abutment tooth, a, denture. adjacent said clasp, a stud extending substantially vertically in relation to said denture and fixed at its lower end to said denture, and a sleeve slidable on said stud and removable irom the upper end of said stud, said sleeve tweensaid clasp and said denture.

2. In an artificial denture, the combination of: a clasp for engagement with an abutment tooth, a. denture. adjacent said clasp, a stud extending substantially vertically in-relation to said denture. and fixed at its lower end to said denture; said stud being non-circular in cross section, and av sleeve slidable on saidstud and removable from the. upper end. of said stud, said sleeve being; secured to said clasp, said stud and said" sleeve permitting relative. vertical, movement between said clasp and: said denture.

3.. In an artificial denture, the combination of} a. clasp.- for engagement with an abutment, tooth, a denture adjacent said clasp, a stud extending; substantially vertically in relation to, said dene ture and fixed at. its. lower end to said denture, said stud being bifurcated, and a sleeve. sl-idable r on said stud and removable from the. upper end.

of said stud, said stud and said. sleeve permitting, relative vertical movement. between said, clasp.

and said denture, said bifurcated stud being e'xpansible against. the inner wallsfoi said sleeve to take up. wear and. maintain said, sleeve.

4. In an artificial denture, the combination of: a clasp for engagement with anabutment tooth, a denture adjacent said clasp, a. stud extending substantially vertically in relation to said denturea-ndfixed at its lower end to said denture, said stud, being non-circular in cross section and bifurcated, and a sleeve slidable on saidstud and removable: from the upper end of said stud, said stud: and: said: sleeve permitting relative vertical movement between said clasp and said denture, said bifurcated, stud being expansi-bleagainst the inn-er walls of, said sleeve. to take up.- wear and. maintain a. snug fit within said sleeve.

'5. In an. artificialv denture, the combination of:- a saddle-having; an artificial tooth mounted thereon, a clasp adapteclto engage an abutment tooth; and retain. said saddlein, position in the mouth, a. stress. relievingv attachment connecting said, clasp and said saddle, said attachment cl uding separable male-andfemale elements. dis posed to. allow relative. vertical movement. between said clasp and said saddle, and a detent for yield. ablyresisting separation of said male andfemale elements. a

6. In an. artificial denture, the combinationyof a saddle having an artificial tooth mounted there on, a clasp adapted to engage, an abutment tooth position in the mouth, a. stress. relieving attachment connecting said.- clasp and said, saddle, said; attachment includ-. ing separable male and female elements. dist posed to allow relative vertical. movement. be". clasp and. said saurldle, and} a detent for yieldably resisting separation of said male said stud and said a snug fit within and female elements, said male and female elements being non-circular in closs section to prevent rotation of said clasp and said saddle about the axis of said attachment.

'7. In an attachment for relieving stresses between a clasp and saddle in an artificial denture, the combination of: a male element formed to provide an upstanding stud, a mounting shank extending radially from said stud, and a sleeve slidable on and removable from said upstanding stud, said stud and said sleeve being mountable between said clasp and said saddle to allow relative vertical movement between said clasp and said saddle.

8. In an attachment for relieving stresses between a clasp and saddle in an artificial denture, the combination of, a male element formed to provide an upstanding stud of non-circular cross section and a mounting shank extending radially from said stud, and a non-circular sleeve slidable on and removable from said upstanding stud, said stud and said sleeve being mountable between said clasp and said saddle to allow relative vertical movement between said clasp and said saddle and prevent relative rotation of said clasp and said saddle about the axis of said stud.

9. In an attachment for relieving stresses between a clasp and saddle in an artificial denture, the combination of z a male element formed to provide an upstanding, bifurcated stud, and a sleeve slidable on said stud, said stud being expansible against the bore of said sleeve, said attachment being mountable between said clasp and said saddle to allow vertical rectilinear movement between said clasp and said saddle.

10. In an attachment for relieving stresses be- 1 REFERENCES CITED UNITED STATES PATENTS 535 Number Name Date 1,449,079 Yirikian Mar. 20, 1923 1,451,718 Stern Apr. 17, 1923 1,502,970 Van Houten July 29, 1924 

